v3.26.1
Schedule H, Part Iv, Line 4i - Schedule Of Assets (Held At End Of Year) (Detail) - EBP 001 [Member] - USD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
EBP, Schedule of Asset Held for Investment [Line Items]    
Entity Tax Identification Number 93-3827109  
EBP, Plan Number 001  
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 37,314,403  
EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution 866,483 [1] $ 932,348
EBP, Asset Held for Investment 38,180,886  
Mutual Fund [Member]    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value 35,920,873  
Common Collective Trust [Member]    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value 140,257  
Common Stock [Member]    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value 1,253,273  
TC Energy Common Stock [Member]    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value 518,568  
South Bow Common Stock [Member]    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 734,705  
Maximum [Member]    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Participant Loan, Interest Rate 9.50%  
Minimum [Member]    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Participant Loan, Interest Rate 3.25%  
Investment, Identifier [Axis]: Common Collective Trust | Mellon Stable Value M    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Mellon Stable Value M [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Common Collective Trust [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 140,257  
Investment, Identifier [Axis]: Common Stock | South Bow Corporation    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] South Bow Corporation [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Common Stock [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 733,632  
Investment, Identifier [Axis]: Common Stock | TC Energy Corporation    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Tc Energy Corporation [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Common Stock [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 517,463  
Investment, Identifier [Axis]: Mutual Fund | Allspring Special Mid-Cap Value R6    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Allspring SpecialMidCapValue R6 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 430,541  
Investment, Identifier [Axis]: Mutual Fund | Baird Core Plus Institutional Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Baird Core Plus Institutional Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 872,192  
Investment, Identifier [Axis]: Mutual Fund | Baron Growth R6    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Baron Growth R6 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 380,086  
Investment, Identifier [Axis]: Mutual Fund | Fidelity® 500 Index Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity 500 Index Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 5,098,663  
Investment, Identifier [Axis]: Mutual Fund | Fidelity® Extended Market Index Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity Extended Market Index Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 2,115,215  
Investment, Identifier [Axis]: Mutual Fund | Fidelity® Government Money Market    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity Government Money Market [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 67  
Investment, Identifier [Axis]: Mutual Fund | Fidelity® Growth CO K6    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity Growth Co K6 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 5,520,833  
Investment, Identifier [Axis]: Mutual Fund | Fidelity® Inflation-Protected Bond Index Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity InflationProtected Bond Index Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 290,524  
Investment, Identifier [Axis]: Mutual Fund | Fidelity® U.S. Bond Index Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity U.S. Bond Index Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 496,882  
Investment, Identifier [Axis]: Mutual Fund | JPMorgan Equity Income Fund Class R6    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Jpmorgan Equity Income Fund ClassR6 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 982,813  
Investment, Identifier [Axis]: Mutual Fund | MFS International Diversification Fund R4    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Mfs International Diversification Fund R4 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 854,115  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Federal Money Market Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Federal Money Market Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 844,797  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2025    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2025 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 1,196,489  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2030    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2030 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 1,820,573  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2035    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2035 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 2,079,556  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2040    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2040 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 1,332,796  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2045    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2045 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 4,019,136  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2050    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2050 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 2,198,096  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2055    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2055 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 1,637,701  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2060    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2060 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 2,579,907  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2065    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2065 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 67,443  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement 2070    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement 2070 [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 15,411  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Target Retirement Income Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Target Retirement Income Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 89,812  
Investment, Identifier [Axis]: Mutual Fund | Vanguard Total International Stock Fund AD    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard Total International Stock Fund Ad [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value $ 997,225  
Investment, Identifier [Axis]: Stock Purchase Account | South Bow Stock Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] South Bow Stock Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Stock Purchase Account [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 1,073  
Investment, Identifier [Axis]: Stock Purchase Account | TC Energy Stock Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Party-in-Interest [true false] true  
EBP, Investment, Issuer Name [Extensible Enumeration] Tc Energy Stock Fund [Member]  
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]  
EBP, Investment, Current Value, Type [Extensible Enumeration] Stock Purchase Account [Member]  
EBP, Asset Held for Investment, Plan Interest in Master Trust, Current Value [1] $ 1,105  
[1] Represents a party-in-interest (Note 5).